A Simple Way to Achieve Legible and Local Controllable Patterning

Subscriber access provided by University of Sussex Library

Article

A Simple Way to Achieve Legible and Local Controllable Patterning for Polymers Based on Near-Infrared Pulsed Laser Jihai Zhang, Tao Zhou, Liang Wen, Jing Zhao, and Aiming Zhang ACS Appl. Mater. Interfaces, Just Accepted Manuscript • DOI: 10.1021/acsami.5b10243 • Publication Date (Web): 30 Dec 2015 Downloaded from http://pubs.acs.org on January 11, 2016

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

ACS Applied Materials & Interfaces is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 25

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Applied Materials & Interfaces

A Simple Way to Achieve Legible and Local Controllable Patterning for Polymers Based on Near-Infrared Pulsed Laser Jihai Zhang, Tao Zhou,* Liang Wen, Jing Zhao, and Aiming Zhang State Key Laboratory of Polymer Materials Engineering of China, Polymer Research Institute, Sichuan University, Chengdu 610065, China. *Corresponding author. Tel.: +86-28-85402601; Fax: +86-28-85402465; E-mail address: [email protected] (T. Zhou)

1

ACS Paragon Plus Environment


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Abstract: This study developed a simple way to achieve legible and local controllable patterning for polymers based on near-infrared (NIR) pulse laser. The polycarbonate-coated nano antimony-doped tin oxide (nano ATO) was designed as a core-shell structure that was tailored to be responsive to a 1064 nm NIR laser. The globular morphology of polycarbonate-coated nano ATO with a diameter of around 2-3 µm were observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). This core-shell structure combined the excellent photo-thermal conversion efficiency of nano ATO and the high char (carbon) residue of polycarbonate. The X-ray photoelectron spectroscopy (XPS) results of polymer patterning plate after laser irradiation demonstrated that through local controlled photochromism, the well-defined legible patterns can be fabricated on the polymer surfaces contribute to the synergistic effect consisting of polycarbonate carbonization and nano ATO photo-thermal conversion. Furthermore, polymers doped with minimal content of polycarbonate-coated nano ATO can achieve remarkably patterning effect. This novel laser patterning approach will have wide promising applications in the field of polymer NIR pulse laser patterning. Keywords: laser patterning, nano antimony-doped tin oxide, carbonization, near-infrared pulse laser, polymer

2


Page 2 of 25

Page 3 of 25

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


1. Introduction Laser, exhibits a unique set of properties of excellent mono-chromaticity, high energy, and directionality, have received considerable theoretical and experimental investigations ever since it was first produced in 1960s.1-13 In the field of laser applications, laser patterning on materials surface (e.g., ceramics, metals, and woods) has emerged as a promising technology for the purposes of product identification and traceability. The obvious advantages of this technology include design flexibility, legibility, short fabrication cycle, and large-scale production. Compared to the blue laser (λ=325 nm) and green laser (λ=532 nm), the equipment of 1064 nm NIR laser has a lowest cost. In the last decades, the cost-effective near-infrared (NIR) laser has been widely applied to fabricate indelible and legible characters or logos on the material surface, mainly including the metals and the ceramics.14-16 From the point of cost and practicality, 1064 nm NIR laser, in practice, are hopefully more widely applied on polymers patterning. To date, however, polymer NIR laser patterning is unavailable due to the intrinsically weak absorption of NIR laser for most polymers. Conventionally, the main method for polymer patterning is still ink printing, which always contains toxic ingredients.17-19 No matter what types of prints to be made, the process always necessarily includes master board production, printing, and drying, which is complex and spends a lot of time.17-19 Therefore, the ink printing on polymers has a high cost. In addition, some problems were also encountered when recycling of these ink printing polymers. For an example, before recycling, the ink on the plastic surface should be scraped off by the manual or the machine; however, the residual ink is always present. Another example, these recycled polymers merely can be used to produce

3



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

low-value colored products after re-extrusion, and the mechanical properties will be seriously reduced due to the gases cause by the ink thermal decomposition.20 Due to environmental and occupational risk associated with ink printing, it is imperative to develop a simple, efficient and environment-friendly approach for polymers NIR pulse laser patterning.21 Conceptually, laser patterning refers to the process in which a high-power laser beam focus on the material surface, resulting in legible pattern with discoloration. Generally speaking, laser patterning black pattern against the light-colored polymer is the result of surface layer carbonization.22 A high char residue is beneficial to the polymer laser patterning to form a legible black mark. Our present investigations focus on high-density polyethylene (HDPE), which is considered as one of the most difficult patterned polymers.23, 24 In recent years, there has been increasing interest in nano antimony-doped tin oxide (nano ATO) due to its intrinsic structure, photo-electricity and chemical properties.25-28 Gao et al.29 investigated nano ATO as smart glass foil contributes to its high absorption in the NIR region. Especially, considering the strong NIR absorption of nano ATO, whether it can be used as an ideal laser absorber for polymers NIR pulse laser patterning? Polycarbonate (PC), in particular, is a thermoplastic aromatic polymer that has been extensively studied over the past 50 years, due to its unique chemical structures and excellent physical properties.30-35 One of the most important characteristics of PC is that it has a high char (carbon) residue kept approximately at 24.5 % at 800 °C, as shown in Figure S1 (Supporting Information). For HDPE, however, the char (carbon) residue at 800 °C was almost zero, as shown in Figure S2 (Supporting Information). Out of this consideration, nano ATO coated by a layer of PC to prepare a PC-coated nano ATO, the as-prepared PC-coated nano ATO can be effectively

4


Page 4 of 25

Page 5 of 25

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


applied to polymers NIR pulse laser patterning. During the process of laser patterning, PC obtains a lot of energy absorbed by nano ATO. This transfer energy is sufficient for making PC carbonization within the range of the laser spot, and fabricates a sharp black pattern on the light-colored polymers surface via the local photochromism.

Figure 1. A schematic illustration of the polymers laser patterning through the local controlled photochromism, where a 1064 nm NIR pulse laser is used in conjunction with a computerized image to pattern polymer surface. Herein, we introduced a novel approach for polymers NIR pulse laser patterning based on nano ATO. The high efficient polymer patterning has been realized through non-contact NIR pulse laser. Compared with the traditional ink printing, the sub-processes of master board production and drying are no longer existed in the laser patterning, only containing laser “printing”. Due to its intrinsically high photo-thermal conversion efficiency, nano ATO converts the absorbed laser energy to make a local controlled carbonization on the polymer surface. To the best of our knowledge, this is the first report on proposing nano ATO for polymers NIR pulse laser patterning. Moreover, PC-coated nano ATO can be designed with a core-shell structure that is tailored to be responsive to NIR laser, in which a much better

5



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

polymer laser patterning can be performed due to a better local photochromism. In the present study, Q-switched pulsed neodymium-doped yttrium aluminium garnet (Nd:YAG, λ=1064 nm) optical fiber pulse laser with a built-in digital galvanometric beam scanning system was employed. Figure 1 illustrates the mainly schematic process of laser patterning on the polymers surface. Furthermore, NIR pulse laser can better control the local photochromism within the range of the laser spot through precisely adjusting the laser energy. Finally, the rapid, well defined patterns of polymers can be conveniently achieved. The proposed approach is more economic, efficient and environmentally friendly. 2. Experimental section 2.1. Materials Nano antimony-doped tin oxide (nano ATO, SnO2:Sb2O3=11.2:1, analyze with XPS as shown in Figure S3 in the Supporting Information; purity: 99.99 %) was supplied by Nanjing Tianxing New Materials Co., Ltd. (China). High-density polyethylene (HDPE, TR144, density: 0.946 g/cm3, melt flow rate: 0.18 g/10 min) was purchased from Sinopec Maoming Company. Polycarbonate (PC, Infino SC-1220R, melt flow rate: 22 g/10 min, 250 °C, 10 Kg; density: 1.2 g/cm3) which was synthesized via interfacial condensation between bisphenol A (oil phase) and phosgene (aqueous phase), was produced by Samsung Chemical Co., Korea. Polypropylene (PP, T30S, density: 0.91 g/cm3, melt flow rate: 3.4 g/10 min, 230 °C, 2.16 Kg) supplied by Lanzhou Petrochemical Industrial Co., China. Nylon 6 (PA6, B3S, density: 1.13 g/cm3) was purchased from BASF, Germany. Polybutylene terephthalate (PBT, 310SEO, density: 1.39 g/cm3) was provided by General Electric, USA. Analytical reagent grade dichloromethane (DCM) was kindly supplied by Chengdu Kelong Reagent, China. All the

6


Page 6 of 25

Page 7 of 25

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


materials were used as received without any further treatment. 2.2. Preparation of polycarbonate-coated nano ATO Polycarbonate-coated nano antimony-doped tin oxide (nano ATO) can be designed with a core-shell structure through a simple high-speed mixer solvent evaporation technique. Briefly, 10.0 g nano ATO was first put into a high-speed mixer. Next, 2.1 g polycarbonate (PC) as a solution in dichloromethane (DCM) was drop-wise added into the high-speed mixer. Further, high-speed mixer agitation was carried out at an ambient temperature for approximately 20 s to ensure DCM volatile completely. The above procedure was repeated five times. The polycarbonate-coated nano ATO thus produced and then followed by vacuum drying at 25 °C for 4 h to remove the residual solvent. Finally, the above-prepared PC-coated nano ATO was taken out of the vacuum and stored in a dry dish until use. The weight ratio of nano ATO and PC in PC-coated nano ATO was 83:17. 2.3. Preparation of polymer patterning plate Firstly, 99.95 g HDPE and 0.05 g nano ATO were mixed uniformly in a high mixing machine for 30 s. Similarly, 99.94 g HDPE and 0.06 g PC-coated nano ATO were mixed uniformly in a high mixing machine for 30 s. In HDPE+PC-coated nano ATO, the content of PC-coated nano ATO is 0.06 g, in which the absolute content of nano ATO is 0.05 g. Then the HDPE composite was prepared using a laboratory twin screw extruder around 150 °C. Finally, the polymer patterning plates (78 mm×65 mm×3 mm) were prepared using a laboratory injection molding machine. The injection processing temperature was 180 °C. 2.4. Characterizations 2.4.1. Powder X-ray diffraction (PXRD)

7



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

PXRD patterns of nano ATO were characterized by a DX-1000 diffractometer using the Cu Kα radiation (λ= 0.15418 nm) induced at 35 kV and 25 mA. 2.4.2. X-ray photoelectron spectroscopy (XPS) The chemical elements of nano ATO and the surface of polymer patterning plates after laser patterning were analyzed by X-ray photoelectron spectroscopy (XPS) using a Kratos XASAM 800 spectrometer (Kratos analysis, UK) operating at the Al Kα achromatic X-ray source (1486.6 eV). 2.4.3. Ultraviolet-visible-infrared (UV-vis-IR) The near-infrared (NIR) absorbance of nano ATO was investigated at room temperature by a UV-vis-NIR spectrophotometer (UV-3600, Shimadzu) in the range from 500 to 2000 nm. 2.4.4. Scanning electron microscopy (SEM) SEM micrographs of the nano ATO, PC-coated nano ATO and the surface of polymer patterning plate after laser irradiation were conducted on a JEOL JSM-7500F field-emission scanning electron microscope at 20 kV. The samples were coated with a thin layer of gold to reduce charging during observation. 2.4.5. Transmission electron microscopy (TEM) TEM characterization of nano ATO and PC-coated nano ATO was performed using a JEOL JEM-2011 microscope with an accelerating voltage of 200 kV. The samples were prepared by dripping diluted nano ATO or PC-coated nano ATO solution onto copper grids. 2.4.6. Thermal gravimetric analysis (TGA) The high temperature charring ability of high density polyethylene (HDPE) and polycarbonate (PC) were measured with a NETZSCHTG 209F1 thermal gravimetric analyzer

8


Page 8 of 25

Page 9 of 25

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


at a heating rate of 10 °C/min in the range of 30-800 °C under a nitrogen atmosphere. The sample size was 10 mg. 2.4.7. Fourier-transform infrared spectroscopy (FTIR) The FTIR spectra of polycarbonate and polycarbonate-coated nano ATO in the region 4000-400 cm-1 were collected using Nicolet iS 50 equipped with a deuterated triglycine sulfate (DTGS) detector. The experiment was run at 4 cm-1 resolution, and the scans of each FTIR spectrum were 20. The collection mode selected attenuated total reflection (ATR) with smart iTR accessory. Because ATR collecting the surface FTIR to determine whether PC was coated over the surface of nano ATO. 2.4.8. Micro-Raman spectroscopy The surface Raman spectra of the polymer plates after laser patterning were carried out on a DXRxi micro-Raman spectrometer (Thermo Fisher Scientific, USA) equipped with a diode laser of excitation of 532 nm and a 25 µm confocal pinhole. The experiment was carried out at a laser power level of 4.0 mW (532 nm), and a 1.0 s exposure time with 900 lines/mm grating. 2.4.9. Determination of parameters for laser patterning Laser patterning experiments were performed on a pulsed Nd: YAG (λ=1064 nm) MK-GQ10B laser machining system (Optical fiber pulse laser power 10 W; Mike Laser Technology Co., Ltd. Kunshan, China) equipped with EZCAD 2.0 software. Considering the optimize utilization of the laser energy, at the beginning of laser patterning, adjust the distance between condenser (field lens) and the polymer patterning plate to make sure to focus the laser on the surface of polymer patterning plate. Through adjusting the parameters

9



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

of the computer-controlled laser scanning system and pulse fiber laser, any laser beam of desired energy can be obtained. In this section, we designed a special computerized vector image for laser patterning. To investigate the optimal laser energy of this patterning process, the laser energy square blocks were patterned as shown in Figure 2. A series of patterning parameters embodied in the form of a coordinate system. The laser scanning speed and pulse duration were fixed at 2000 mm/s and 100 µs, respectively. The pulsed frequency range of the pulsed laser system was chosen from 20 to 100 kHz, while the laser power was expressed as a percentage range from 10 to 100 % (1-10 W, for example: 60% equals to 6 W). The horizontal axis represented the pulsed frequency of the laser (20, 30, …, 90, 100 kHz), and the vertical axis represented the laser power (10, 20, …, 90, 100%). Under laser irradiation we can obtain ninety laser energy windows (4×4 cm2). After laser patterning, the laser energy windows which were formed a legible black pattern were the ideal laser patterning windows.

Figure 2. A computerized vector image with the coordinate system (left), and the computer-rendered image of the patterned polymer plate after laser patterning (right).

10


Page 10 of 25

Page 11 of 25

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Figure 3. Spectroscopy and morphology characterization of the nano ATO. (a) ultraviolet-visible-infrared (UV-vis-IR) spectroscopy (the green areas of the bottom left corner: visible light region; the blue arrow: λ=1064 nm); (b) Powder X-ray diffraction (PXRD) patterns of nano ATO powders in red and reference PXRD peaks (represented as vertical blue bars) of SnO2 cassiterite structure (ICSD PDF no. 77-0452); (c) Scanning electron microscopy (SEM) image of the nano ATO, scale bar: 100 nm; (d) Transmission electron microscopy (TEM) image of the nano ATO, scale bar: 10 nm. 3. Results and discussion 3.1. Characterization of nano ATO Spectroscopy and morphology characterization of the nano ATO are shown in Figure 3. The NIR absorbance of nano ATO was investigated using UV-vis-IR spectroscopy [Figure 3 (a)], it can be seen that nano ATO appears a strong absorbance around 1064 nm and exhibits an excellent optical transparency in the visible-light region. This UV-vis-IR feature of ATO was also reported by Gao et al.,29 which indicates a highly absorption efficiency for NIR laser. Figure 3 (b) illustrates the powder X-ray diffraction (PXRD) patterns of nano ATO, which is matched well with the SnO2 cassiterite structure (ICSD PDF no. 77-0452) and consistent with the results of previous studies.26, 36, 37 In the present study, SnO2:Sb2O3=11.2:1, no diffraction peaks of antimony oxide were observed due to the antimony oxide entering into the tin oxide 11



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

lattice. This phenomenon also reported by Wang et al. that no structural change was observed in the SnO2 cassiterite lattice when the content of antimony-doped was below 15 mol%.38 The estimate average crystallite size from the FWHM of (101) peak is approximate 6.7 nm, and the specific calculation method can refer to supporting information. To further investigate the morphology of nano ATO, we performed the SEM and TEM experiments. The SEM image [Figure 3 (c)] indicates that the nano ATO exclusively consisted of nanospheres with narrow particle size distribution. The TEM image [Figure 3 (d)] reveals that the nanospheres had a uniform diameter of around 6-8 nm, which matched well with the average crystallite sizes analyzed by PXRD. 3.2. Characterization of PC-coated nano ATO Attenuated total reflection (ATR) is a powerful characterization method for infrared spectroscopy analysis that provides information on chemical groups on the material surface. Figure 4 (a) shows the ATR FTIR spectra of polycarbonate and polycarbonate-coated nano ATO in the region 3200−2700 cm-1 and 1900−700 cm-1. The bands at 3060 cm-1 and 3040 cm-1 are attributed to aromatic C−H asymmetrical stretching and symmetrical stretching. The bands at 2970 cm-1 and 2932 cm-1, 2873 cm-1 are attributed to C−H asymmetrical stretching and symmetrical stretching of −CH3 groups.39 The band at 1775 cm-1 is attributed to the stretching vibration of C=O groups in PC main chains.40 Benzene ring breathing vibration41 appears in the region of 1620−1510 cm-1, two bands can be distinguished, including 1600 cm-1 and 1505 cm-1. 1462 cm-1 is the deformation vibration of −CH3 groups.41 The bands at 1230 cm-1 and 1194 cm-1 are assigned to the asymmetrical −O−C=O stretching vibrations of the carbonate group, while the band at 1163 cm-1 is probably a C−(CH3)2 skeletal mode. The 12


Page 12 of 25

Page 13 of 25

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


band at 1014 cm-1 is attributed to the O−C−O symmetric stretching vibration of the PC main chains.40-42 FTIR analysis demonstrates an important feature of PC wrapped on the surface of nano ATO, confirmed the existing of core-shell structure. SEM was employed to characterize the morphology of the PC-coated nano ATO. Figure 4 (b) is the microscopic morphology of the PC-coated nano ATO particles. It can be observed that the most of particles are spherical. Inevitably, a small amount of particles are extremely irregularly shaped. The TEM image in Figure 4 (c) clearly shows a differential contrast with darkened nano ATO (as the red arrows) embedded in the lighter PC matrix. Compared with the nano ATO, the particle diameters of the PC-coated nano ATO are around 2-3 µm, which is much larger than that of raw nano ATO. That is to say, the core of a PC-coated ATO particle contains many ATO nanoparticles and ATO aggregates.

Figure 4. (a) Attenuated total reflectance FTIR spectra of PC and PC-coated nano ATO in the region 3200−2700 cm-1 and 1900−700 cm-1. PC: blue line, PC-coated nano ATO: red line; (b) SEM image of PC-coated nano ATO; (c) TEM image of PC-coated nano ATO. 3.3. Determination of parameters (laser energy) for laser patterning

13



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

In laser patterning, the phenomenon is that the thin polymer surface layer subjected to laser scanning occurs local discoloration, presenting the black patterns against the light-colored polymer matrix. By contrast, the polymer surface without subject to laser scanning does not appear color change. Commonly, the NIR pulse laser penetration depth range from micrometer to millimeter order with the effects of laser output power at the same scanning speed. In Figure 5(a), no laser patterning is observed on the polymer surface due to neat HDPE having no absorption of 1064 nm NIR laser. The laser patterning phenomenon of HDPE, however, obtains significant enhance when five-ten thousandths (0.05 wt.%) of nano ATO is incorporated [Figure 5 (b)]. Furthermore, the pattern resolution is enhanced with laser power increasing from 1 W to 10 W. Zheng et al.43 studied the irradiation of TPE/TiO2 by short pulse ultraviolet laser, and a similar result was also reported that the pattern resolution was enhanced by the increase of laser power. In this study, not only the tendency of pattern resolution with the variation of NIR pulse laser power, but also that of pattern resolution with the variation of the pulse frequency of NIR laser can be clearly observed in Figure 5. Interestingly, in Figure 5 (c), at the same nano ATO content, HDPE doped with PC-coated nano ATO achieved more clearly patterned effect in the same laser energy windows. From the viewpoint of the pattern resolution, the PC-coated nano ATO prepared in this study is more suitable to apply in HDPE laser patterning due to a better local photochromism behavior under the same laser energy.

14


Page 14 of 25

Page 15 of 25

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Figure 5. (a), (b) and (c) are the digital photographs of the pattern window of neat HDPE, HDPE doped with nano ATO, and HDPE doped with PC-coated nano ATO after laser patterning, respectively. (d), (e) and (f) are the corresponding SEM images of laser pattern window (60,100) and enlarged images of the left. (g), (h) and (i) are the corresponding XPS analysis at the pattern window (60,100) after laser patterning. SEM was employed to characterize the surface morphology of the laser patterning plate. As shown in Figure 5 (d), the SEM images demonstrate no melting and ablation on neat HDPE surface. This indicates that the NIR laser have no effect on the neat HDPE. In contrast, we can see that HDPE doped with nano ATO and HDPE doped with PC-coated nano ATO both appear etching pit on the polymer surface. The reason is probably due to the micro-bubbles under the surface layer of HDPE ruptured in the action of laser scanning, just like “volcano eruption”. To further explore the reasons for black pattern, the XPS analyses were carried out. The results reveal that the carbon contents of neat HDPE, HDPE doped with nano ATO, and HDPE doped with PC-coated nano ATO after laser patterning are 85.74%, 87.04%, and 93.52%, respectively. The XPS results clearly demonstrate that the black 15



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

pattern formed after NIR pulse laser irradiation is contributed to the carbonization. Moreover, the more local carbonization presents on the polymer surface, the higher pattern resolution is obtained. The micro-Raman spectroscopy of the surface of the polymer plates after laser patterning was also carried out, and the Raman spectra are shown in Figure S4 in the Supporting Information. For HDPE doped with nano ATO and HDPE doped with PC-coated nano ATO, it clearly shows the appearance of a new broad diffusion band in the region 1000−2000 cm-1 after laser patterning. This broad diffusion band is assigned to the amorphous carbon in Raman spectroscopy,44 which indicates the generation of the amorphous carbon on the polymer surface after laser patterning. Laser patterning tests demonstrate an important feature that the patterning effect depends on material properties, pulse frequency, and laser power under the same scanning speed. Figure 6 illustrates the simple schematic of the laser patterning HDPE doped with nano ATO and PC-coated nano ATO, respectively. Under the 1064nm pulse laser irradiation, nano ATO strongly absorbing the laser energy and convert it into heat. The local carbonization of HDPE occurs around nano ATO. By contrast, for PC-coated nano ATO, the polycarbonate wrapped on the ATO surface subject to heat occurs a greater degree of local carbonization, forming a more distinct black pattern on the HDPE surface.

16


Page 16 of 25

Page 17 of 25

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Figure 6. Scheme of the laser patterning of HDPE doped with nano ATO and PC-coated nano ATO through the local photochromism, respectively, where a 1064 nm NIR pulse laser is used in conjunction with a computerized image to pattern polymer surface. 3.4. Application of laser patterning via the local controlled photochromism

As mentioned above, the pattern resolution is determined by the laser output power and the laser absorption degree of the materials being patterned. In this section, the laser patterning parameters were set at (80, 70) with a scanning speed of 2000 mm/s. To illustrate the application of laser patterning, a computerized image of the Sichuan University badge [Figure 7(a)] was accurately patterned onto the HDPE surface at desired positions. As shown in Figure 7, the patterns of laser patterning were captured using a digital camera. For the neat HDPE [Figure 7 (b)], there has no absorption of the NIR pulse laser to fabricate patterns, and basically no practical value. In Figure 7 (c), however, the patternability of HDPE is increased dramatically after incorporated merely 0.05 wt.% nano ATO, and this phenomenon is ascribed to a strong laser 17



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

absorbance of nano ATO. In comparison, at the same nano ATO content (0.06 wt.% PC-coated nano ATO), Figure 7 (d) shows a more clearly pattern with the high resolution and well-defined edges contributed from the enhanced local polycarbonate carbonization by pulse laser irradiation. The real-time contrast of the laser patterning process for neat HDPE and HDPE doped with PC-coated nano ATO are shown in Supplementary Movie S1. In this study, PC-coated nano ATO has been also successfully incorporated in other polymer matrices, including polypropylene (PP), Nylon 6, polybutylene terephthalate (PBT), and polycarbonate (PC). The digital photos of the patterns of these polymers are shown in Figure S5 in the Supporting Information, and the real-time processes of laser patterning are also provided in Supplementary Movie S2 in the Supporting Information. As expected, the patterns with the high resolution and well-defined edges are also obtained.

Figure 7. A comparative investigation of (a) the computerized image of Sichuan University badge, (b) laser patterning on neat HDPE, (c) laser patterning on HDPE incorporated with 0.05 wt.% nano ATO, and (d) laser patterning on HDPE incorporated with 0.06 wt.% PC-coated nano ATO (in which the absolute content of nano ATO is actually 0.05 wt.%). The patterns by laser patterning were operated on the same laser patterning parameters (80,70) 18


Page 18 of 25

Page 19 of 25

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


with a scanning speed of 2000 mm/s.

4. Conclusions In summary, this study is the first report on proposing nano ATO as a convenient, highly 1064 nm pulse laser absorber for laser patterning on the polymer surface. Furthermore, we successfully constructed PC-coated nano ATO core-shell particles through a simple high-speed mixer solvent evaporation method. The as-prepared PC-coated nano ATO exhibited a significant photo-thermal conversion efficiency contributed from the strong NIR laser absorption of nano ATO. The most important finding from this study is that nano ATO and PC-coated nano ATO can be applied in polymer NIR pulse laser patterning for the rapid, well defined patterns through the local controlled photochromism. This study provided a guideline to design and develop laser patterning additives for polymers. The results of laser patterning demonstrated that thin polymer surface layer subject to the laser scanning occurred local discoloration, and the more local carbonization presented on the polymer surface, the higher pattern resolution was obtained. This novel laser patterning approach shows exceptional precision, resolution, and reproducibility, will potentially revolutionize the field of polymer NIR pulse laser patterning.

Supporting Information. TG and DTG curves of PC and HDPE; XPS of nano ATO, calculations of crystal size of nano ATO; surface Raman spectra of neat HDPE and the doped HDPE after laser patterning; the digital photos of the patterns of PP, PA6, PBT, and PC after laser patterning; the real-time movies of laser patterning. 19



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 20 of 25

Acknowledgements The authors would like to thank Analysis and Testing Center, Sichuan University assistance with the electron microscopic analysis, and XPS measurements from the Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences. This work was supported by the National Natural Science Foundation of China (Grant No. 51473104, 51003066), and State Key Laboratory of Polymer Materials Engineering (Grant No. sklpme2014-3-06). References 1.

Jauregui, C.; Limpert, J.; Tuennermann, A. High-Power Fibre Lasers. Nat. Photonics

2013, 7, 861-867. 2.

Guo, P.; Zhuang, X.; Xu, J.; Zhang, Q.; Hu, W.; Zhu, X.; Wang, X.; Wan, Q.; He, P.;

Zhou, H.; Pan, A. Low-Threshold Nanowire Laser Based on Composition-Symmetric Semiconductor Nanowires. Nano Lett. 2013, 13, 1251-1256. 3.

Hide, F.; Diaz Garcia, M. A.; Schwartz, B. J.; Andersson, M. R.; Pei, Q. B.; Heeger, A. J.

Semiconducting Polymers: A New Class of Solid-State Laser Materials. Science 1996, 273, 1833-1836. 4.

Liu,

Y.-K.;

Lee,

M.-T.

Laser

Direct

Synthesis

and

Patterning

of

Silver

Nano/Microstructures on a Polymer Substrate. ACS Appl. Mater. Interfaces 2014, 6, 14576-14582. 5.

El-Kady, M. F.; Kaner, R. B. Direct Laser Writing of Graphene Electronics. ACS nano

2014, 8, 8725-8729. 6.

Lyutakov, O.; Tůma, J.; Huttel, I.; Prajzler, V.; Siegel, J.; Švorčík, V. Polymer Surface

Patterning by Laser Scanning. Appl. Phys. B 2013, 110, 539-549. 7.

Rahimi, R.; Ochoa, M.; Yu, W.; Ziaie, B. Highly Stretchable and Sensitive Unidirectional

Strain Sensor via Laser Carbonization. ACS Appl. Mater. Interfaces 2015, 7, 4463-4470. 8.

Hurtado, J. M.; Lowe, C. Ammonia-Sensitive Photonic Structures Fabricated in Nafion

Membranes by Laser Ablation. ACS Appl. Mater. Interfaces 2014, 6, 8903-8908. 20


Page 21 of 25

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


9.

Strong, V.; Wang, Y.; Patatanyan, A.; Whitten, P. G.; Spinks, G. M.; Wallace, G. G.;

Kaner, R. B. Direct Sub-Micrometer Patterning of Nanostructured Conducting Polymer Films via a Low-Energy Infrared Laser. Nano Lett. 2011, 11, 3128-3135. 10. Orlandi, M.; Caramori, S.; Ronconi, F.; Bignozzi, C. A.; El Koura, Z.; Bazzanella, N.; Meda, L.; Miotello, A. Pulsed-Laser Deposition of Nanostructured Iron Oxide Catalysts for Efficient Water Oxidation. ACS Appl. Mater. Interfaces 2014, 6, 6186-6190. 11. Yetisen, A.; Qasim, M.; Nosheen, S.; Wilkinson, T.; Lowe, C. Pulsed Laser Writing of Holographic Nanosensors. J. Mater. Chem. C 2014, 2, 3569-3576. 12. Barchanski, A.; Funk, D.; Wittich, O.; Tegenkamp, C.; Chichkov, B. N.; Sajti, C. L. Picosecond Laser Fabrication of Functional Gold–Antibody Nanoconjugates for Biomedical Applications. J. Phys. Chem. C 2015, 119, 9524-9533. 13. Ushiba, S.; Shoji, S.; Masui, K.; Kono, J.; Kawata, S. Direct Laser Writing of 3D Architectures of Aligned Carbon Nanotubes. Adv. Mater. 2014, 26,5653-5657. 14. Holzinger, G.; Kosanke, K.; Menz, W. Printing of Part Numbers Using a High Power Laser Beam. Opt. Laser Technol. 1973, 5, 256-265. 15. Noor, Y. M.; Tam, S. C.; Lim, L. E. N.; Jana, S. A Review of the Nd: YAG Laser Marking of Plastic and Ceramic IC Packages. J. Mater. Process. Technol. 1994, 42, 95-133. 16. Amara, E.; Haïd, F.; Noukaz, A., Experimental Investigations on Fiber Laser Color Marking of Steels. Appl. Surf. Sci. 2015. 351,1-12. 17. Malaguarnera, G.; Cataudella, E.; Giordano, M.; Nunnari, G.; Chisari, G.; Malaguarnera, M. Toxic Hepatitis in Occupational Exposure to Solvents. World J. Gastroentero. 2012, 18, 2756-2766. 18. Kiurski, J.; Marić, B.; Adamović, D.; Mihailović, A.; Grujić, S.; Oros, I.; Krstić, J. Register of Hazardous Materials in Printing Industry as a Tool for Sustainable Development Management. Renew. Sust. Energ. Rev. 2012, 16, 660-667. 19. Donald, J. M.; Hooper, K.; Hopenhayn-Rich, C. Reproductive and developmental toxicity of toluene: a review. Environ. Health Persp. 1991, 94, 237-244. 20. Gecol, H.; Scamehorn, J. F.; Christian, S. D.; Grady, B. P.; Riddell, F. E. Deinking of Water-Based Ink Printing From Plastic Film Using Nonionic Surfactants. J. Surfactants Deterg. 2002, 5, 363-374. 21



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 22 of 25

21. Graff, G. Additives Make Possible Laser Marking of Polyolefin Components. Mod. Plast. 1996, 73, 24-25. 22. Makee, T. J. How Lasers Mark. Plast. Technol. 1996, 35, 11-18. 23. Rentzhog, M.; Fogden, A. Print Quality and Resistance for Water-Based Flexography on Polymer-Coated Boards: Dependence on Ink Formulation and Substrate Pretreatment. Prog. Org. Coat. 2006, 57, 183-194. 24. Földes,

E.;

Tóth,

A.;

Kálmán,

E.;

Fekete,

E.

Surface

Changes

of

Corona-Discharge-Treated Polyethylene Films. J. Appl. Polym. Sci. 2000, 76, 1529-1541. 25. Peng, Q.; Kalanyan, B.; Hoertz, P. G.; Miller, A.; Kim, D. H.; Hanson, K.; Alibabaei, L.; Liu, J.; Meyer, T. J.; Parsons, G. N. Solution-Processed, Antimony-Doped Tin Oxide Colloid Films Enable High-Performance TiO2 Photoanodes for Water Splitting. Nano Lett. 2013, 13, 1481-1488. 26. Liu, G.; Xu, J.; Wang, Y.; Wang, X. An Oxygen Evolution Catalyst on Antimony Doped Tin Oxide Nanowire Structured Support for Proton Exchange Membrane Liquid Water Electrolysis. J. Mater. Chem. A 2015, 3, 20791-20800. 27. Song, N.; Zhu, H.; Liu, Z.; Huang, Z.; Wu, D.; Lian, T. Unraveling the Exciton Quenching Mechanism of Quantum Dots on Antimony-Doped SnO2 Films by Transient Absorption and Single Dot Fluorescence Spectroscopy. ACS nano 2013, 7, 1599-1608. 28. Stroppa, D. G.; Montoro, L. A.; Beltran, A.; Conti, T. G.; da Silva, R. O.; Andres, J.; Longo, E.; Leite, E. R.; Ramirez, A. J. Unveiling the Chemical and Morphological Features of Sb-SnO2 Nanocrystals by the Combined Use of High-Resolution Transmission Electron Microscopy and ab Initio Surface Energy Calculations. J. Am. Chem. Soc. 2009, 131, 14544-14548. 29. Gao, Y.; Wang, S.; Kang, L.; Chen, Z.; Du, J.; Liu, X.; Luo, H.; Kanehira, M. VO2-Sb:SnO2 Composite Thermochromic Smart Glass Foil. Energy Environ. Sci. 2012, 5, 8234-8237. 30. Yee, A. F.; Smith, S. A. Molecular-structure Effects on the Dynamic Mechanical Spectra of Polycarbonates. Macromolecules 1981, 14, 54-64. 31. Nozaki, K.; Nakano, K.; Hiyama, T. Optically Active Polycarbonates: Asymmetric Alternating Copolymerization of Cyclohexene Oxide and Carbon Dioxide. J. Am. Chem. Soc. 22


Page 23 of 25

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


1999, 121, 11008-11009. 32. Al-Azemi, T. F.; Bisht, K. S. Novel Functional Polycarbonate by Lipase-Catalyzed Ring-Opening

Polymerization

of

5-Methyl-5-Benzyloxycarbonyl-1,3-Dioxan-2-One.

Macromolecules 1999, 32, 6536-6540. 33. Darensbourg, D. J.; Wilson, S. J. Synthesis of Poly(indene carbonate) from Indene Oxide and Carbon Dioxide-A Polycarbonate with a Rigid Backbone. J. Am. Chem. Soc. 2011, 133, 18610-18613. 34. Park, J. H.; Jeon, J. Y.; Lee, J. J.; Jang, Y.; Varghese, J. K.; Lee, B. Y. Preparation of High-Molecular-Weight Aliphatic Polycarbonates by Condensation Polymerization of Diols and Dimethyl Carbonate. Macromolecules 2013, 46, 3301-3308. 35. Bendler, J. T.; Boyles, D. A.; Edmondson, C. A.; Filipova, T.; Fontanella, J. J.; Westgate, M. A.; Wintersgill, M. C. Dielectric Properties of Bisphenol A Polycarbonate and Its Tethered Nitrile Analogue. Macromolecules 2013, 46, 4024-4033. 36. Rockenberger, J.; zum Felde, U.; Tischer, M.; Troger, L.; Haase, M.; Weller, H. Near Edge X-ray Absorption Fine Structure Measurements (XANES) and Extended X-ray Absorption Fine Structure Measurements (EXAFS) of The Valence State and Coordination of Antimony in Doped Nanocrystalline SnO2. J. Chem. Phys. 2000, 112, 4296-4304. 37. Nutz, T.; Haase, M. Wet-Chemical Synthesis of Doped Nanoparticles: Optical Properties of Oxygen-Deficient and Antimony-Doped Colloidal SnO2. J. Phys. Chem. B 2000, 104, 8430-8437. 38. Wang, Y.; Chen, T. Nonaqueous and template-free synthesis of Sb doped SnO 2 microspheres and their application to lithium-ion battery anode. Electrochim. Acta 2009, 54, 3510-3515. 39. Apai, G.; McKenna, W. P. Surface-Analysis of Polycarbonate Thin-Films by High-Resolution Electron-Energy Loss Spectroscopy. Negative Ion Resonances and Surface Vibrations. Langmuir 1991, 7, 2266-2272. 40. Hopfe, I.; Pompe, G.; Eichhorn, K. J. Ordered Structures and Progressive Transesterification in PC/PBT Melt Blends Studied by FTIR Spectroscopy Combined with DSC and NMR. Polymer 1997, 38, 2321-2327. 41. Valmikanathan, O. P.; Ostroverkhova, O.; Mulla, I. S.; Vijayamohanan, K.; Atre, S. V. 23



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

The

Effect

of

Synthesis

Procedure

on

the

Structure

Page 24 of 25

and

Properties

of

Palladium/Polycarbonate Nanocomposites. Polymer 2008, 49, 3413-3418. 42. Dybal, J.; Schmidt, P.; Baldrian, J.; Kratochvil, J. Ordered Structures in Polycarbonate Studied by Infrared and Raman Spectroscopy, Wide-Angle X-ray Scattering, and Differential Scanning Calorimetry. Macromolecules 1998, 31, 6611-6619. 43. Zheng, H.; Lim, G. C. Laser-effected Darkening in TPEs with TiO2 Additives. Opt. Laser. Eng. 2004, 41, 791-800. 44. Itoh, K.; Kudryashov, I.; Yamagata, J.; Nishizawa, T.; Fujii, M.; Osaka, N. Raman Microspectroscopic Study on Polymerization and Degradation Processes of a Diacetylene Derivative at Surface Enhanced Raman Scattering Active Substrates. 2. Confocal Raman Microscopic Observation of Polydiacetylene Adsorbed on Active Sites. J. Phys. Chem. B 2005, 109, 271-276.

24


Page 25 of 25

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


For TOC only

25


A Simple Way to Achieve Legible and Local Controllable Patterning

Recommend Documents